The present invention relates to a ratchet wrench and, more particularly, to a reversible ratchet wrench.
U.S. Pat. No. 6,629,477 discloses a reversible ratchet wrench including a handle and a driving member rotatably mounted in the handle. The driving member can couple with a socket for engaging with a fastener, such as a screw or nut. The fastener can be rotated when a user rotates the handle. A retaining member is slideably received in a retaining recess in the handle and selectively engages with the driving member. A direction control member is rotatably mounted in a receiving chamber of the handle. A pressing member and an elastic member are mounted in a first receiving recess in the direction control member. The pressing member is biased by the elastic member to press against the retaining member. When the direction control member is rotated, the position of the retaining member pressed by the pressing member can be changed to change the driving direction of the driving member.
In assembly, the direction control member is firstly placed into the receiving chamber, and the pressing member and the elastic element are passed through the receiving chamber into the first receiving recess. Finally, the retaining member and the driving member are mounted to the handle in sequence. The pressing member is retained in the handle to prevent the direction control member from disengaging from the receiving chamber. Grease is filled between the retaining member and the driving member to permit smooth engagement and smooth disengagement therebetween. The reversible ratchet wrench cannot be completely sealed during assembly such that oil from the outside and scraps generated by friction between the driving member and the retaining member accumulate between the driving member and the retaining member, adversely affecting the engagement and disengagement therebetween. In a case that the retaining member cannot disengage from the driving member due to improper operation by a user, the pressing member will deform and damage due to excessive pressing by the retaining member if the user keeps applying a rotational force in a reverse direction. Thus, the reversible ratchet wrench malfunctions and cannot be used. Furthermore, when the pressing member is pressed into the first receiving recess due to excessive pressing, the pressing member loses its limiting function, leading to disengagement of the direction control member from the receiving chamber. If the user is working with his or her head raised for tightening a fastener above his or her head, the direction control member falling from the receiving chamber could hit the head and endangers the user.
Furthermore, water or sweat could enter the reversible ratchet wrench after a period of time of use, leading to rusting of the driving member and the retaining member and, thus, adversely affecting smooth engagement and/or disengagement therebetween, which also causes damage to the reversible ratchet wrench.
Thus, a need exists for a novel reversible ratchet wrench that mitigates and/or obviates the above disadvantages.